There are many mobile card readers in the market available right now. These readers allow the user to swipe or dip a credit card/debit card/gift card with magnetic strip or smart chip and in turn convert the data from the card into electrical signals. Once the data is converted into electrical signals, it is transmitted to the mobile device (e.g., smart phone, tablet, PC) via audio jack, serial port, or other mobile device interface.
In particular, mobile card readers that interface with the mobile device via the audio jack have become almost ubiquitous. One issue with such devices is in developing or updating the device driver every time a new mobile device is released and ensuring that the audio protocols work on this device. If the audio protocols do not work, the driver needs to be updated. Among other things, this delays the ability to support a given mobile device with the card reader and also adds cost and complexity for the card reader provider.
Some companies have tried to avoid this issue by using Bluetooth for communication between the reader and the mobile device. Bluetooth has its own issues.